<!DOCTYPE html>
<html lang="en">

<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<meta http-equiv="X-UA-Compatible" content="ie=edge">
	<title>摄像头拍照</title>
	<style>
		video {}
	</style>
</head>

<body>
	<video id="video" width="480" height="320" controls>
	</video>
	<div>
		<button id="capture">拍照</button>
	</div>
	<canvas id="canvas" width="480" height="320"></canvas>
	<img src="" id="img" alt="">
	<script>
		//访问用户媒体设备的兼容方法
		function getUserMedia(constraints, success, error) {
			if (navigator.mediaDevices.getUserMedia) {
				//最新的标准API
				navigator.mediaDevices.getUserMedia(constraints).then(success).catch(error);
			} else if (navigator.webkitGetUserMedia) {
				//webkit核心浏览器
				navigator.webkitGetUserMedia(constraints, success, error)
			} else if (navigator.mozGetUserMedia) {
				//firfox浏览器
				navigator.mozGetUserMedia(constraints, success, error);
			} else if (navigator.getUserMedia) {
				//旧版API
				navigator.getUserMedia(constraints, success, error);
			}
		}

		let video = document.getElementById('video');
		let canvas = document.getElementById('canvas');
		let context = canvas.getContext('2d');

		function success(stream) {
			//兼容webkit核心浏览器
			let CompatibleURL = window.URL || window.webkitURL;
			//将视频流设置为video元素的源
			console.log(stream);

			//video.src = CompatibleURL.createObjectURL(stream);
			video.srcObject = stream;
			video.play();
		}

		function error(error) {
			console.log(`访问用户媒体设备失败${error.name}, ${error.message}`);
		}

		if (navigator.mediaDevices.getUserMedia || navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia) {
			//调用用户媒体设备, 访问摄像头
			getUserMedia({ video: { width: 480, height: 320 } }, success, error);
		} else {
			alert('不支持访问用户媒体');
		}

		document.getElementById('capture').addEventListener('click', function () {
			context.drawImage(video, 0, 0, 480, 320);
			document.getElementById("img").src = canvas.toDataURL('image/png', 1)
		})
	</script>
</body>

</html>